This invention relates in general to speed governors for motor vehicles, and particularly to improvements in the safety system to assure that the governor releases when the brakes are actuated.
Many motor vehicles are equipped with speed governors, known as "cruise controls". The cruise control enables the driver to select a speed, which will then be automatically maintained by the control system. The system normally has a servo that opens and controls the throttle and a control means for sensing and controlling the speed. The control means can either hold the speed, or it can actuate an accelerator means to advance the throttle or a decelerator means to allow the throttle to retract. Normally the accelerator means is a valve that provides vacuum to a vacuum servo. The decelerator means is a valve that relieves the vacuum in the vacuum servo. Also, a brake switch is provided for signalling the control circuit to decelerate when the brake pedal is depressed.
Some systems have a second switch or safety release means that also will cause the throttle to retract when the brake pedal is depressed. The second system is an added safety feature that is needed in case either the brake switch, the accelerator means, or the control circuit fails. If a component of the safety circuit fails, in addition to a component in the main release circuit, then the throttle may not release, possibly causing an accident.